Abstract

• In this research, the optimum condition for the preparation of cellulose acetate from maize straw powder, wheat straw powder and sawdust powder could be determined by four different acetylation methods. Firstly, the three sample powders were dewaxed. In the preparation of cellulose, the dewaxed sample powders were refluxed only with 15% NaOH for 9 h. Then the delignified sample masses were bleached with 5% sodium hypochloride solution for 24 h and neutralized with 5% acetic acid and water. The resultant neutral cellulosic pulps were acetylated with acetic anhydride and acetic acid in the presence of concentrated sulphuric acid as a catalyst using magnetic stirrer in method 1. In method 2, the apparatus used is ultrasonic cleaner instead of magnetic stirrer. In the third method, acetylation was carried out by using one more solvent (toluene) with ultrasonic cleaner. In the fourth method, solvents used were similar as in method 3 but with different catalyst (perchloric acid) instead of using sulphuric acid. The yield percentages of three cellulose acetates were determined and compared and then identified by FT IR spectroscopic analysis. At the same time, more reliable method that gave a good yield % and more purified product was observed.